Design and diagrams decision
StampDy
A single developer can reproduce the core stamp editor and PDF stamping (multi-week effort), but the full paid product—especially hosted e-signature features and legal-ready signing records—requires heavier compliance and operational work that makes a complete replacement impractical for one person.
Visit website↗$19.9/mo
$239/yr
Read off the official pricing page.
$100one-off76 h to build
$0/mo6 h/mo upkeep
On cash alone, building overtakes the subscription at 1 seat.
Open-source builds that already do this
Every project below is open source and already does this job today. Fork one, self-host it, or take the parts you need - the build prompt further down assumes an empty file, and this is the shortcut past that. Licences differ; check the one on each card before you ship. All StampDy alternatives, with the arithmetic →
What a replacement has to do
- Design a stamp in a browser SVG editor, export as PNG/SVG/PDF/etc., place stamp into PDFs and optionally request signatures.
What it still won’t have
- Built-in AI stamp generation credits and AI-driven auto-create features
- Hosted cloud library with cross-device saved projects (unless implemented)
- Bundled e-signature workflow with signer links, email invitations, reminders and completion certificates
- ‘Legal-ready’ signing records, SHA-256 hashing, and completion summaries
- Priority support, hosted payments and billing UX
What remains hard
- Compliance and regulation
Download signed PDF, signing summary, and completion certificate PDF SHA-256 hash, activity audit trail, and legal-ready signing records
First-year cost
Keep paying
Paying is—cheaper in year one.
On cash alone, building overtakes the subscription at 1 seat.
Money you would actually spend
Time you would spend
—
What you would spend
What we assumed
The verdict above measures whether you could build it. This one is only about money.
Runnable build prompt
Build a minimal self-hosted stamp-maker and PDF-stamping service using React + TypeScript frontend and Node.js + Express backend. Frontend: an SVG-based editor (use fabric.js or plain SVG) supporting shapes, layered text, circular-text layout, image upload, live preview, undo/redo, and local autosave. Backend: endpoints to accept SVG and render/export to PNG/JPG/PDF/EPS (use sharp, svg2png, and pdf-lib), and a PDF stamping endpoint that opens an uploaded PDF, places/embedds the rendered stamp at specified coordinates, and returns a flattened PDF (use pdf-lib). Storage: optional S3-compatible bucket for exported assets. Payments: stubbed Stripe integration (out of scope to enable billing). Include error handling, input validation, unit tests for export and PDF stamping logic, and end-to-end tests for the editor → export flow. Out of scope: legally-admissible e-signature workflows (signer emails, audit certificates, SHA-256 evidence), AI stamp generation credits, and multi-tenant billing.
How we checked
How the score was reached
- Partly verdict base52
- An open-source build was found+5
- 5 cited sources+3
- Price verified on pricing page+3
- 3/3 assessment runs agreed+4
- Hard moats found in the evidence-3
- Evidence score64
The base comes from the verdict. Everything under it is a check that either happened or did not, and each one is a fact frozen in this record rather than a judgement made at render time - so the same evidence always produces the same number.
How scoring works →Cited sources · 5
Every page the run actually retrieved.
- official productStampDy — product
- official pricingStampDy pricing
- official docsStampDy docs/features
- open sourceGraphiteEditor/Graphite
- open sourcemethodofaction/Method-Draw
Integrity checks
What held up, and what did not.